The prior art is replete with various inventions directed to the methods of providing phosphorescent textile fibers and used therefore. However, none of these inventions are directed to a phosphorescent indicator in which the luminescent properties decay at a predetermined rate corresponding to the ware of the product. Notably, many synthetic yarns are subject to molecular breakdown in the presence of ultraviolet light. The longer the exposure, the greater the loss of tensile strength in the synthetic yarns, such as nylon. Nothing in the prior art uses a phosphorescent indicator to correlate the exposure of synthetic yarns to ultraviolet light with the loss of tensile strength in the synthetic yarns as a result of the ultraviolet light exposure.
Accordingly, it is an object of the present invention to provide a phosphorescent indicator for webbings made of synthetic yarns which measure time exposure to ultraviolet light.
It is another object of the present invention to provide such a phosphorescent indicator for webbings in which the luminescent property of the indicator decay at a predetermined rate as a result of time exposure to ultraviolet light which is correlated to the molecular breakdown of the synthetic yarns to indicate the condition of the webbing.